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The costs of mischoosing are not uniform across individuals

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Matching habitat choice is a particular form of habitat selection based on self?assessment of local performance that offers individuals a means to optimize the match of phenotype to the environment. Despite the advantages of this mechanism in terms of increased local adaptation, examples from natural populations are extremely rare. One possible reason for the apparent rarity of matching habitat choice is that it might be manifest only in those segments of a population for which the cost of a phenotype–environment mismatch is high. To test this hypothesis, we used a breeding population of sockeye salmon (Oncorhynchus nerka) exposed to size-dependent predation risk by bears, and evaluated the costs of mischoosing in discrete groups (e.g. male versus females, and ocean?age 2 versus ocean?age 3) using reproductive life span as a measure of individual performance. Bear preference for larger fish, especially in shallow water, translates into a performance trade-off that sockeye salmon can potentially use to guide their settlement decisions. Consistent with matching habitat choice, we found that salmon of similar ocean?age and size tended to cluster together in sites of similar water depth. However, matching habitat choice was only favoured in 3?ocean females – the segment of the population most vulnerable to bear predation. This study illustrates the unequal relevance of matching habitat choice to different segments of a population, and suggests that ‘partial matching habitat choice' could have resulted in an underestimation of the actual prevalence of this mechanism in nature. informacion[at]ebd.csic.es: Camacho & Hendry (2020) Matching habitat choice: it's not for everyone. Oikos DOI 10.1111/oik.06932


https://onlinelibrary.wiley.com/doi/full/10.1111/oik.06932
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Home is where I grew up

Home is where I grew up

In this study, a cross-fostering experiment was conducted between an oakwood and an adjacent conifer plantation to investigate the role of early experience and genetic background in habitat selection in a pied flycatcher (Ficedula hypoleuca) population. Most birds returned to breed in the forest patch where they were raised, indicating that settlement decisions are determined by individuals' experience in their natal site, rather than by their genetic background. Nevertheless, a third moved away from the rearing habitat and, as previously observed in unmanipulated individuals, dispersal between habitats was size-dependent. Pied flycatchers breeding in the oak and the pine forests are differentiated by body size (the latter being smaller in size), and analyses of genetic variation at microsatellite loci now provide evidence of subtle genetic differentiation between the two populations. Phenotype-dependent dispersal may contribute to population structure even at small spatial scales. Nevertheless, the strong tendency to return to the natal patch regardless of their body size might lead to maladaptive settlement decisions and thus constrain the potential of phenotype-dependent dispersal to promote microgeographic adaptation. informacion[at]ebd.csic.es: Camacho et al (2016) Natal habitat imprinting counteracts the diversifying effects of phenotype-dependent dispersal in a spatially structured population. BMC Evolutionary Biology 16:158. DOI: 10.1186/s12862-016-0724-y


http://link.springer.com/article/10.1186/s12862-016-0724-y